Austenitic and duplex stainless steels, SUS316LN and DIN1.4462, were heavily cold rolled up to 92%. Hetero-nanostructure mainly composed of deformation twins and shear bands in addition to lamellar was homogeneously developed. The above component microstructures were finer than 100 nm. The cold rolled samples possessed quite high tensile strength over 1.5 GPa with ductility about 10%. The well-balanced mechanical properties were comparable with those of ultrafine-grained 316L austenitic stainless steel processed by multi-directional forging. Therefore, specific mechanical properties could be attained by simple cold rolling. When the cold-rolled samples were aged at 773 K, tensile strength was further raised up to 2.6 GPa. However, it showed strong anisotropy in the mechanical properties. Tensile strength normal to the rolling direction was higher strength than that along rolling direction. The marvelous mechanical properties achieved would be caused by the heterogeneous nanostructures, where dense distribution of nano-twins, nano-shear bands and nano lamellar partially impeded dislocation motion to derive superior balance of strength and plasticity.
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